Systems for freezing water and other liquids in large quantities are well known. Many of these systems are used in building environmental systems such as water chillers and the like. These devices are used to take advantage of energy savings which are typically available in low energy demand hours such as early morning. These devices typically include refrigeration coils through which a saturated refrigerant liquid is pumped to cool the coil. The pump and compressor used to provide this liquid through the coil are typically operated with electrical energy. During low demand times, the compressor and pump are operated at lower electrical energy costs to cool the coil. Water is trickled through the coils and as it cools, it freezes on the coils and ice builds outwardly from the coils.
During the day when cool air is needed to maintain the temperature within a building at a comfortable level, air is circulated through the coils prior to being pumped through a building. As long as the coil remains encased in the ice, the compressor and pump need not be operated or are operated less frequently to supply refrigerant and cool the coils. The ice provides a heat exchanger surface which removes heat from the air prior to its circulation through the building. As this air cooling system continues to operate, the amount of heat absorbed by the ice begins to melt the ice about the coils. The water drips into a collection tank below the coils where it is stored. Later, during the low demand hours, the coils are supplied with refrigerant to cool them and the water is pumped from the collection reservoir to the top of the system so that it may trickle about the coils for freezing. Thus, the ice is used to reduce energy costs for cooling a building by time shifting the demand for electrical energy required to cool the building.
Large commercial ice freezers are also known. These devices typically use hollow members which are operated in much the same ways as the refrigerating coils of the building cooling systems described above. These hollow devices are typically arranged in a horizontal or vertical fashion and controls are provided for the controlled flow of refrigerant through the members. Water is provided at a constant rate on the outside surfaces of the hollow members so that it cools and freezes as it traverses along the surface area of the member. The ice is permitted to build to a preferred predetermined thickness at which time, the refrigerant liquid is no longer supplied to the hollow members. Instead, a defrosting gas is supplied to the member to warm the outer walls of the freezing member. Thus, as these walls warm, they melt the ice nearest the wall of the member causing the ice to fall. If the freezing members are arranged in a horizontal fashion, a surface to catch the falling ice may be located proximate the freezing member so the ice may be removed and then uniformly cut for bagging and the like. When the coils are arranged in a vertical manner, the ice typically falls off the freezing member and breaks into pieces which are then collected and bagged for commercial distribution.
Within the fruit juice industry, juice processors are confronted with the problem of providing juice to the market as it is needed throughout the year. This problem stems from the fact that there is typically only one harvest of fruit in a year. For example, the harvesting of oranges occurs at approximately a single time throughout the United States. As a consequence, the oranges are sent to fruit processors who extract the juice within weeks of the harvest. Thus, the fruit processors effectively have their entire supply for a market year in a relatively short time. Normally, the market is unable to purchase and consume the entire amount of juice processed at the harvest. As a result, fruit juice processors have sought ways to preserve the quality of the processed juice so they may supply the market steadily throughout the year.
In response to this need for preserving fruit juice, fruit processors or juice distributors initially built very large refrigerated warehouses for storing the juice. After the juice is processed, it is stored in 55 gallon drums sterilized for food and stacked within the refrigerated warehouses. These warehouses are maintained at temperatures at which the juice freezes within the drum. As the juice is needed, the barrels are removed from the refrigerated warehouse and permitted to thaw so the juice may be removed from the drums and appropriately packaged for market.
A number of problems arise from this type of storage of the processed juice. One problem arises from the time required for the juice to freeze. In many of these warehouses, the temperature is not uniformly maintained and the placement of numerous barrels within an area of the warehouse at one time requires an exchange of a great deal of heat from the juice before it freezes. As a result, not all of the barrels freeze at the same time and in some cases a period as long as three weeks is required before all the juice freezes. During that time period, some of the juice may begin to experience flavor degradation which may affect the taste of the juice within the drums.
Another problem with the large refrigerated warehouses is the efficiency of utilizing the storage space within the warehouses. Because the drums have a general cylindrical shape, they leave air spaces between adjacent drums as they are pushed together. As a result, a substantial amount of the space within the warehouse is not utilized to store juice.
Another problem with the warehouse storage method is the cost of the drums. To contain the amount of juice typically obtained by a processor or distributor, a significant number of barrels are needed. These barrels must be specially treated to hold the juice without contaminating the juice. Additionally, the transportation of the drums from the juice collection facility to the warehouse and the stacking operations at the warehouse damage the storage drums. The cost of buying the drums, treating the drums and replacing the damaged drums may be significant for the juice processor or distributor.
Attempts to use the chillers and block freezers previously known to freeze large amounts of juice or other liquids have not been successful for a number of reasons. For one, the coils of the previously known systems are not sufficiently sized to freeze the large amounts of juice that a typical processor would need to freeze. Another problem is the ice harvest method which requires the collection of the frozen liquid after it falls. Because the juice is not sold in plastic bags as is commercially available ice, the frozen juice fragments would have to be swept into some type of rigid container to provide sufficient structure so the juice may be stacked in the warehouse. Storage in conventional plastic bags used for ice is not feasible because the lower bags in the storage stack would probably break from the weight of the stack. As a result, the known chillers and freezers do not reduce the expense associated with drums and the like.
Another problem with existing chillers and freezers is the design of the coils. The coils are typically metal tubes that are smoothly bent to form a U-shaped structure. One is coupled to the high side of a refrigeration pump or compressor and the second end is coupled to the low pressure or return side of the cooling system. In the compressors typically associated with such systems, the refrigerant becomes entrained with lubricating oil. This entrainment occurs in the compressor as the oil which lubricates the movable member that compresses the refrigerant is squeezed through the gaskets and rings about the compression chamber. This oil greatly increases in viscosity in the coldest areas of the coil and tends to collect there, coating the interior heat exchange surface of the coil which reduces the freezing capacity and efficiency of the coil. The accumulation of the oil may be sufficient to block a coil because the temperatures needed to freeze the juice should be maintained for a relatively long time to freeze the large amounts of juice required by a juice processor.
What is needed is a system that freezes the amount of juice available at a fruit harvest without requiring large numbers of rigid containers such as metal drums and the like. What is needed is a method of freezing large amounts of liquid that can be efficiently stored. What is needed is a freezing structure that can freeze large amounts of liquid without accumulating lubricating oil sufficient to block the structure or significantly impede the freezing process. What is needed is a method of freezing large amounts of liquid in a relatively short period of time.